Method of and apparatus for melting glass by electricity



May 5, 1936.' D. sTl-:NHoUsE 2,039,853

, METHOD 'OF AND APPARATUS FOR MELTING GLASS BY ELECTRICITY Filed Oct. 5, 1933 2 Sheets-Sheet l No z we IIIII HHUIHIIHIIIIIIIIIIII' www gva/ventola jaa/d Nien/hazme 2 Sheets-Sheet 2 bbocwbgf D. STENHOUSE Filed Oct. 5,

METHOD OF AND APPARATUS FOR MELTING GLASS BY ELECTRICITY May 5, 193.6.y Y

Patented May 5, 1936 METHOD OF AND APPARATUS FOR MELT- ING GLASS BY ELECTRICITY David Stenhouse, Washington, Pa., assignor to Hazel-Atlas Glass Company, WheelingW.'Va., a corporation of West Virginia Application October 3, 1933, Serial No. 692,014?

. c 2 Claims. The invention relates to the melting of glass batches, and particularly to a novel method and which the glass is periodically ruptured at a series of pointsalong the furnace thereby causing the formation of electric arcs atthe pointsl -of separation. The apparatus `employed preferably includes a revolving or oscillating furnace, but it is not essential for the invention relates broadly to rupturing the glass and causing electric arcs to pass at the points of separation. Obviously a revolving oroscillating furnace is not essential in carrying out such a method.

The melting of glass by electricity is old and well known, and it is also common knowledge that molten 'glass is a conductor of electricity. In accordance with the present invention the molten glass periodically acts as a conductor, and during these periods the glass is caused to draw apart at various parts throughout. the length of the furnace, resulting in a series of arcs 'between the I separating masses of glass.

The invention will'be clearly understood by those -skilled' in the art, from the following detailed description when takenin connection with the accompanying drawings illustrating one form sential to the broad principle involved to employ either a rotating or an oscillating furnace. apparatus for melting glass by electricity, inj

of apparatus for carrying out the novel method. y

:In the drawings:

Figure. 1 is a side elevational View of the-ap paratus; parts belngbroken away.

Figure 2 is a vertical transverse sectional viewn taken on line 2 2 of Figure 1.

Figure 3 is a vertical longitudinal sectiona view taken on lin'e 3 3 of Figure 2; and Figure .4 is a detail view ofl one form of driving mechanism for rotating the furnace.A

Referring to the vdrawings in more detail,- numeral i refers to a rotating tank or furnace, `which is preferably enclosed* in the metallic casing 2. lThe furnace is provided with acharging opening 3 through which the batch is fed, and a discharge opening 4 through which the melted and refined glass is delivered. The present invention is not concerned with the disposal of the glass when it leaves the furnace, and-merely for purposes of illustration va revolving pot This shown as receiving'the glass fromv the furnace.

Circling the casing 2 are bands 6 andyr'I which are revolvably supported upon rollers 6' and 1.

In the specific form illustrated the furnace is continuously rotated, though of course it may be oscillated if, preferred. 'A ring gear-8 is secured to the casing 2, and a pinion 9 carried by ishaft I Il meshes with the ring gear., The shaft I0 is driven by a motor I I through gear connections I2 to a gear reduction contained in the reduction case I3. Obviously any desired mechanism may be employed for either rotating or oscillating the furnace; and as stated hereinbefore it is not es- Batch may be supplied to the furnace either intermittently or continuously by any desired means, though I prefer to employ the mechanism shown herein for continuously feeding the batch to the furnace. The batch is supplied to a hopper I 4 from a -source of supply (notl shown), and a screw conveyer I5 delivers it to the interior of the furnace. The screw may be driven by any desired means, as by a motor I6 through a speed reduction gearing enclosed in the case I1 and sprocket chain i8. As will appear hereinafter electricity is not employed in the initial stage of melting the batch; recourse being had to a burner for first bringing the glass batch to a molten state,

`after which the electric means is put into operation and continued indefinitely.l The specific construction shown herein for initially melting the batch includes a burner I9 which is inserted through the hollow shaft of the ,screw conveyer. The gas or other fuel under pressurel is supplied to the burner I9 by a pipe 20, and suicient air to support complete combustion is drawn in `Vby the suction created; though if preferred the supply of air may be had from av source of compressed air, the rate of. flow being controlled so as to give the desired type of'ame.

refractory blocks 22, but these blocks 22 project farther inwardly than do the first-mentioned blocks, so that they' extend into the glass at times during the rotation of the furnace. The blocks preferably extend the full length of the furnace, but it will be apparent that many different arrangements of the blocks are possible, and hence the particular arrangement shown herein is to be considered merely as illustrative. of the furnace in the direction of the arrow, causes each of the blocks 2,2 to successively lift the viscous molten glass above its normal level. As the rotation continues the glass on the projecting portion of the block will flow back to the mass of glass in the bottom of the tank. During this flow the glass will rupture and separate at many points, and at these points an electric arc will be caused to pass between the glass in the bottom of the tank and the glass cataracting from the projections.

The rotation other end of the furnace.

arcs to pass at the points where the glass is'drawing apart during the continued rotation of the tank, will now be described. At intervals about the furnace are a number of blocks or segments 23, which preferably extend substantially the full length of the furnace. These blocks are electric conductors and are made of any suitable conducting material. 'I'he number and arrangement of the conductors may be varied as desired, but in the specific form illustrated there is a conductor above each of the refractory blocks 22, so that current will pass through the glass during its separation period, as shown at the right hand side of Figure 2.

Numeral 24 refers to a commutator band, to which are clamped a number ofi electrodes 25. Each electrode passesthrough an opening 28 and is intimately connected with its adjacent conductor 23. The openings are larger than 'the electrodes, and to further provide against electric contact with the casing 2, bushings 21 of'nonconducting material are preferably inserted in the openings.

The commutator band 24 is supported in spaced relation from the furnace casing by a number of brackets 22. and these brackets are insulated from the commutator band by insulating material; and the commutator segments 29, 30, 3l, 32, l) andijl being likewise insulated'from each other. Numerals 35 and 36 refer to brushes ad `justably mounted in the terminals 31 and 38 of the brush holder 39. This brush holder is prefer.-

by means of a burner. For this purpose an ordinary burner is shown, but obviously any desired means may be employed forinitially melting the batch; and if preferred it may be originally/melted elsewhere and then be delivered to the rotat"l ing furnace. A fter the initial melting of the -batch the electric means for continuing the melting indefinitely, is thrown into operation. Dur-- ing this continuous electric melting operation the batch is preferably continuously supplied to the furnace, by the means illustrated or by any other desired means; and the melted and refined glass is preferably delivered continuously from the If preferred, the batch may be fed intermittently, and whether the batch is fed continuously or intermittently the melted and refined glass may be delivered continuously or intermittently. Also, the invention is not lim` ited to any particular apparatus for carrying out the novel method, and while a continuously rotating ful-haceis shown, and the method will be described in connection with a rotating furnace, yet it will be understood that an oscillating furnace may also be employed; and, in fact, they invention is not limited to, either a rotating or oscillating furnace, for the broad method here involved may be carried out by widely different apparatus.

revolves the inwardly extending blocks 22 will successively lift a portion of the glass above its normal level in the bottom of the tank. During the continued rotation oi' the tank the glass will start to flow back from the particular block to the body of glass, and eventually the flowing stream will rupture, as illustrated in Figures 2 and 3. This rupturing or separation ofthe glass will occur at many points, and at each of these points an electric arc will occur, so that arcs are occurring throughout the length of the furnace. And, of course, this occurs when each of the inwardly projecting blocks comes to a posi- A tion where a `separation takes place between the electrodes 25 associated with these particular commutator segments,v through the conductor I, blocks 23 associated with these electrodes, and

`through the molten glass.

A current of electricity having been set up, arcs will occur when the glass is ruptured as described hereinbefore, and, of course, this rupturing of the glass occurs at various points throughout the length of the furnace. As the furnace continues to rotate the brushes'35 and 36 will pass from the commutator `segments 30 and 29, respectively, and will pass l onto the segments 29 and 34, respectively; and

this will occur whenthe tank has been rotated to a position where the glass is flowing from the next succeeding block 22, This continues as long as the tank is in operation, current being caused to pass through the glass every time one of the blocks 22 reaches a point where the glass has been lifted by one of the blocks 22 and is ilowing back to join the body of glass in the bottom of the 'tankL Thus the arcing occurs periodically during the continued rotation of the furnace, and throughout the length of the furnace.

Having fully described the invention what 1 claim is:

1. Apparatus for melting batch material in a body of molten glass including a furnace, means for rotating the furnace, a plurality of members projecting into the interiorof the furnace for successively separating portions of molten glass from the main body'of glass in the furnace, conductors arranged above and below each of the 'inwardly projecting members, and means for successively establishing a current between the conductors associated with each of mid members, as each member successively becomes operative to separate portions of glass 2. 'I'he method of continuously melting batch material in a body of-molten glass in a moving tank, which consists in originally reducing a glass batch to a molten state, adding batch material to the molten glass, causing the molten glass to periodically become separated by movement of thetank, and establishing an electric arc be- 

